With the recent growth of technology, various kinds of electronic devices such as a personal digital assistant (PDA), an electronic organizer, a smart phone, and a personal computer are being released.
In consideration of user's convenience, many recent electronic devices adopt a touch display (or referred to as a touch-sensitive display or a touch screen) capable of performing both an input function of receiving a touch input and an output function of displaying a screen. Further, as the size of a screen area increases and also the resolution of a display increases, user demands for handwriting input, picture memo, etc. using the touch display are also increasing.
The electronic device including the touch display may perform various functions in response to an input by an external input device such as a stylus pen as well as an input by a user's body (e.g., a hand), thus increasing the convenience and diversity of input actions on the touch display. However, in general, the electronic device merely performs a function in response to a touch or proximity input by the external input device, but fails to distinguish the external input devices from each other or manage distinctive information about the respective external input devices.